In a gas chromatograph, a carrier gas is introduced into a column from a sample introduction part together with a sample, and each sample component is separated while the carrier gas passes through the column. Each sample component separated in the column is detected by a detector connected to the column. The connection of the column to a sample introduction part or a detector can be performed via a column attachment device.
The column attachment device is provided with, for example, a ferrule, a ferrule receiving part, and a ferrule pressing part. The ferrule is attached to the column by being swaged in a state in which the column is inserted. And, by fixing the ferrule attached to the column by pinching between the ferrule receiving part and the ferrule pressing part, the column can be attached to the column attachment device (see, for example, the following Patent Document 1).
In a conventional column attachment device as exemplified by Patent Document 1, a ferrule pressing part is screwed in the ferrule receiving part and attached thereto. Concretely, screw threads are formed on the inner peripheral surface of the cylindrical ferrule receiving part, and screw grooves are formed on the outer peripheral surface of the tip end part of the ferrule pressing part to be screwed in the ferrule receiving part.
FIGS. 10A to 10C are schematic cross-sectional views for explaining an attachment work flow of a column 101. As shown in FIG. 10A, initially, a column 101 is inserted into a ferrule pressing part 102, so that it is set to a state in which the tip end part of the column 101 is protruded from the ferrule pressing part 102. Thereafter, as shown in FIG. 10B, the ferrule 103 is inserted into the tip end part of the column 101 and the positioning of the column 101 to the ferrule 103 is performed. Then, the ferrule 103 is swaged.
As described above, after the ferrule 103 is attached to the column 101, as shown in FIG. 10C, the ferrule pressing part 102 is screwed in the ferrule receiving part 104, so that the ferrule 103 is fixed between the ferrule receiving part 104 and the ferrule pressing part 102. The ferrule receiving part 104 is attached to a sample introduction part or a detector which is a connection target of the column 101.